Thermostatic electric switch



Jan. 3, 1933. A M; E. sTALL-:Y 1,892,858

TH-MOSTATIC ELECTRIC SWITCH Filed sept. s, 1929 2 sheets-sheet 2 l 20 /5 /l'l /2 43 112' l 42' 28 4 G G 3v 4b INVENJ'OR ATTORNEY 4Patented Jan. 3,* 1933 [UNITED sl'a'rasv PATENT vorificev runas E. sumar; or raconta, wasnrmrron, Assrenoa 'ro aan sro'r Janneman: co. me., or raconta, WASHINGTON, a coaroaarroir or wasnnre'ron rnaaxosraa'rc nLEcmaIc-'swrcn applicatiun mea september s, 1929. serial no. saaaso.

This invention relates to improvements in I felectric switches adapted to be operated .by

the rise'and fall of the temperature ofelectric water heaters, hot water storage tanks 5 and other apparatus in lconnection, with which the switch is arranged to operate.

When electric heaters in connection with suitable storage tanks are used as thesourcel of hot water supply7 for .domestic and other purposes, a serious azardincident thereto is l the over heating of the storage water which often results in the production of steam and the backin up of the water past the waterv 4meterwhic is usually ruined thereby; and it results `have been experienced -by negligent v or carelessv persons who have failed to discony f neet their heaters when the storage tank wasvr filled with hot water.

2. The object of this improvement is to provide a thermostat electric switch that is ada ted to automatically disconnect electrical eating devices when predetermined temperatures produced bv the same are exceeded; and to automatically connect said devices when said temperatures are not exceeded. 'Another object. is to provide a switch of the class described that is simple and rugged in constructionand reliable in its operation.

i. 3 A further object is to provide a thermostat electric switch that will respond quickly to yvariations in the temperature of the object on which it is installed.

A'still further object is to provide a thermostat switch that is easy to install and to adjustin order to compensate for the weary of the contacts.

A. final object is to provide a switch of the kind described that is readily adaptable to a wide range of yuses without change in the working elements of the switch mechanism.

Other objects of the invention will be ap parent from the following detailed description of a preferred form of the invention which is clearly illustratedin the accompanying drawings, in which:

f Fig. 1 is a vertical section through the enclosing cover with the line switch removed showing the front elevation of the thermostat switch'mechanism.

is common knowledge that even more serious.

. electric water heater.

Fig. 5 is a detached perspective view of the switch actuating yoke.

Fig. 6 is a` detached perspective view of co the movable switch contact arm.

Fig. vi is a transverse sectional view through the supporting base and housing of the device in a form adapted for installation'v vin connection with hot water storage e5 tanksv and the like, disclosing a plan view of ,the thermostat switch mechanism.

Fig. 8 is an exteriorv plan view of the device installedV on such a tank.

Like reference numerals are used to indicate like parts throughout the drawings in which 10 is the thermostatkelectric switch mechanism proper which is adaptedY to be actuated by what is known in the art as an 'ether cell 11.- The cell 11 has an annular 75 flange 12 that ts snugly in an annular recess 13 in the rearward side of a base frame 14 to which the ether cell is clamped by means of a subbase 15, having a correspondin annu-v lar projection 16 and screws 17. Tie subeo base is of such shape and proportion as to facilitate the mounting of the switch directly on the housing of a circulation type electric water heater 18 by means lof clamplng straps 19 secured at one end in slot 2O of subbase 85 lugs 21, preferably by means of taper pins 22. The other ends 23 of the straps 18 are bent outwardly and drilled to receive a bolt 24 which is used to clamp the subbase securely to the heater or other device as shown clear- 90 1y in Figs. 4 and 8.

An oval aperture 25 in base 14 surrounded by a wall 26 so shaped at its outward edge as to lit snugly against base 18 of the heater, is adapted to receive one end of conduit nipple 27 the other end of which is screwed into a threaded aperture in the base of the heater. A standard conduit bushing 27 is used as an additional means of removably securing the thermostat switch to the heater.

"Thelswitchr mechanisrnof` the device is mounted on projections-28 .and`i29normal top.Y

the upper portion of base 14 as shown clearly in Fig. 2. The lower stationary contacts 30 and terminal screws 31 pass through cylindrical apertures 32 in' projections 28 and 29 and are insulated therefrom preferably by means of mica sleeves 33 and mica Washers 34.` vMetal'washers 35and nuts 36 serve to secure contacts `30 in position-and to connect one end of flexible conductors 37 to terminal screws 31. The projecting threaded portions 30 and 3l of contacts 3() and 31 respectivelyl together with washers and nuts 36 serve as terminals to electrically connect conductors 38 and 39 of the lcircuit to becontrolled.

The movable contacts 40 of the switch are mounted in apertures 41 on movable contact arms 42 and electrically insulated therefrom preferably by mica insulating sleeve 33 and mica washers 34; metal washers 35 andnuts 36 on the threaded projections 40 of the contacts serving to clamp the contacts and 1 insulating elements lirmly to movable arms 42 as seen best in Figs. 1 and 2. 1 Arms 42 and the appended movable contacts are p ivotally mounted on pin 43 which passes through .holes 44v in the up-turned lugs-42 of the arms and through holes 45 in lugs 28 of base 14. l`he length of the arms is suchthat the faces oi the movingr lugs 42 accurately with contact faces of stationary contacts 30. These contact faces are. preferably of a special composition known in the art as Hardy metal.

Flexible conductors 37 are electrically insulated by means of glazed porcelain beads 46, and their remaining ends are connected able contacts regis .r

to movable contacts 40 by means of metal washers 35 and special nuts 47. These serve also as weights .to load the movable arms so the force of gravity will assure the closing of the electric circuit through contacts1 30 and 40.

A pressed metal yoke 48 having upturned ends 48 with aligned holes 49 and a down turned lug 48" `with tapped hole 5,0, is provided with side projections 51 which engage the rearward edge of the inner upturned lugs 42 of contact arms 42when pivotally mounted inposition on pin 43 as shown clearly in Figs. 1 and 3. A screw 52 is so adjusted in tapped hole 50 l of the yoke that with its end bearing against the concaved snap plate 11 of ether celly 11, the projections 5l of yoke 48 will be a short distance from but not touchof arms 4 2 when contacts 3() and 40 are closed. The adjustment thusV secured is maintained by tightening lock nut 53 against lug 48".

The upturnedend 14 and partition wall 14 o'baSe 14 together with the side walls of metal cover 58 form a switch box or compartment in which a standard double pole single -throw indicating switch 53 is mounted by means of screws 54 passing through holes provided in ears 53 and engaging tapped holes 55 in lugs 56. Aperture 57 is adapted4 to re- 39 connecting to terminals 31 of the switch mechanism also pass through aperture 57 and through nipple 27 in the base casting to the terminals of the heater or other device to be controlled.'

After the switch has been installed and ad justed as described cover 58 is removably'secured in position by means of screws 59 which engage the tapped holes in the metal strip 53 of switch 53. These screws are regularly employed to secure the metal cover plate in position after the switch is mounted in a metal box. Supplementing screws 59 is a screw 60 which engages a tapped hole in the top of base casting 14 as seen best in Fig. 2.

As will be seen in the drawings, the several elements of the device are in the positions required for a flow of current from conductors 58 through circuit control switch 53, through conductors 38 thence through the insulated terminals, contacts and other parts of the thermostat switch mechanism 10 to conductors 39 connected to the heating element ofthe water heater.

Obviously the low of current may be broken manually by depressing handle 61 of switch 53 thus throwing the switch to the oil' position when the required quantity of hot water has been obtained. In case the current inadvertently should be left on, or in case it is desired tol completely fill the storage tank with hot water, the current will continue to flow after the circuit is closed until the water in the heater raises to the temperature at which ether cell 11 is designed to operate. lVhen that temperature is reached plate 11 snaps to its outward position due to the increased vapor pressure within the cell thus breaking-the connection between contacts 30 and 40 due to the upward movement of the movable contacts 40 resulting from the operation of the coacting mechanism as previously described.

It will be notedin Fig. 2, that the rearward or vcupped portion of ether cell 11`is adapted to be mounted in close proximityto the wall of the water heater, thus enabling it to respond quicklyto the variations in temperature. This greatly reduces the time lag between the occurrence of the criticaltemperatures and the operations of the thermostat switch, as compared with other devices here- By substituting a subbase l5 of different curvature and using longer clamping straps 19, the device may be mounted at any convenient elevation directly on the hot water storage tank or other container, as shown clearly in Figs. 7 and 8; and a wide range of operating temperature limits are made possible by substituting ether cells designed to operate at the temperature desired within the range of possibilities of this type of equipment. It is obvious that a wide variety of adaptations and operating temperatures are thus made both possible and practical without changing the construction of the principal arts of the device.

y invention is not necessarily limited to the details of construction shown and deJ scribed in this specification, as the inventiony may be employed in other forms that wouldsuggest themselves to those skilled in the art without departing from the spirit of the '1nvention.

Having thus described my invention, what I claim and desire to have protected by Letters Patent is:

1. A thermosatic electric switch embodying partment in series connection with said switch means in said upper compartment.

2. A thermostatic electric switch, embodyingja vertically disposed frame base, horizontal integral fixed supports extending outwardly from said'frame base, ixedcontact members carried by said fixed supports, horizontal movable contact members pivoted on said frame base, an ether iilled thermostat cell secured to said frame base, and means pivoted on said frame base for transmitting the snapping movement of said thermostat cell to said movable contact members for moving the same to make and break contact with said fixed contact members.

3. A thermostatic electric switch embodying a vertically disposedframe base, an upper and a lower set of fixed horizontal integral supports extending outwardly from said frame base, fixed contact members carried by said lower set of fixed supports, horizontal movable contact members pivoted on said frame base and arranged to make and break Contact with said fixed contact members, a thermostat cell for operating said movable contact members, terminal means secured to said upper set of fixed supports,

flexible conductors connecting said terminal means and said movable contact members.

4:. A thermostatic electric switch embody,- ing a vertically disposed frame base, horizontal fixed supports extending outwardly from said frame base, contact members on said fixed supports, a pivot pin mounted in the frame base and extending crosswise thereM of above said fixed supports, an actuating member mounted on said pivot pin, a screw adjustable in said actuating member and extending rearwardly through said frame base, a thermostat cell engaged by the rear end of said screw, horizontal movable contact arms supported on ,said pivot pin on each side of said actuating member and arranged to be engaged and moved by said actuating member and contact members on the outer ends of said movable Contact arms.

5. A thermostatic electric switch embodying a vertically disposed frame base, hoi-i zontal fixed supports extending outwardly from said frame base, contact members sup ported on and insulated from said fixed supports, a pivot pin mounted in the frame base and extending crosswise thereof above said fixed supports, an actuating member mounted on said pvot pin, a screw adjustable in said actuating member and extending rearwardly through said frame base, a thermostat cell secured to the frame base and arranged'to be engaged by the rear end of said screw, means securing the frame base to an object of' variable temperature with the cell in close proximity to the object, horizont-al movable contact arms supported on said pivot pin on each side of said actuating member, lugs on the actuating member arranged to engage and lift said contact arms, contact members on the outer ends of said movable contact arms arranged to engage said fixed contact members, and weights for lowering the outer ends of said movable contact arms.

6. A thermostatic switch embodying a vertically disposed frame base, a subbase secured'to said frame base, a thermostat cell supported between the subframe and the frame base and having a disc like side cas pable of snapping inwardly and outwardly in response to changes of temperature, screw means engaging the movable side of said cell and extending through said frame base, a member pivoted on said frame base and Asupporting said screw, horizontal pivoted switch arms engaged by said member and arranged to be lifted thereby, movable electrical contacts carried by the outer ends of said pivoted arms, and fixed contacts arranged to be engaged by said movable contacts.

7. A thermostatic switch, embodying a vertically disposed frame base, a subbase secured to said frame base, `a thermostat cell supported between the subbase and the frame base, and having a disc like side capable of snapping inwardly and outwardly in response Gti 30 n for securingsaid v tion of said switch by said to changes of temperature, gaging the movable side of said cell and extending through said frame base, a member pivoted on said frame base and supplorting saidr screw, horizontal pivoted switc arms enga ed by said member and arranged lto be v lifte thereby, movable electrical contacts carried by the outer ends of said pivoted arms, fixed contacts arranged tobe engaged 'y by said movable contacts, fixed terminal means on the base plate, and iexible conduc-` tors connecting the movable contacts with the fixed terminal means.

8. A thermostatic electric switch embody-y ing a subbase having a thermostat aperture of relatively large size capable o receiving a' thermostat extending) therethrough, 'meansfor securing said sub ase to a receptaclefor fluid of varying temperature. a base framev removably secured to said subbase, a thermop stat cell in said .aperture in close proximity to `the surface of said receptacle and supported by clamping between said subbase and i said base v"frame, an electric switch mounted on said base frame, and means for the operathermostat cell.

9. A thermostatic electric switch embodying a subbase having a thermostat aperture of relatively large size capable of receiving Y a thermostat `extending therethrough, means v subbase to a receptacle for vfluid of varying temperature, `a ilanged` i stat vcell to said subbase,

stat cell. i y

The fore oing .speciiication signed at thermostat cell in said aperture in close proximity to the surface of said receptacle, a base `frame removably secured to'said subbase and arranged to clamp the flangeof said thermoan electric switch mounted on said base frame,y and means for the operation of said switch by said thermoi Seattle, Wa ingaan, this 22nd day of August MILES E. STALEY. n

SCIOW 11168118 enn 

